1. Field of the Invention
The present invention relates generally to disk drives, and in particular to a disk drive including a magnetic element support with primary and secondary magnetic flux paths.
2. Description of the Prior Art
The typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to a disk drive base of the HDA. The head disk assembly includes at least one disk (such as a magnetic disk), a spindle motor for rotating the disk, and a head stack assembly (HSA). The printed circuit board assembly includes a servo control system in the form of a disk controller for generating servo control signals. The head stack assembly includes at least one transducer head, typically several, for reading and writing data from and to the disk. The head stack assembly is controllably positioned in response to the generated servo control signals from the disk controller. In so doing, the attached heads are moved relative to tracks disposed upon the disk.
The head stack assembly includes an actuator assembly, at least one head gimbal assembly, and a flex circuit assembly. A conventional “rotary” or “swing-type” actuator assembly typically includes a rotary actuator having an actuator body. The actuator body has a bore and a pivot bearing cartridge engaged within the bore to facilitate rotational movement of the actuator assembly between limited positions about an axis of rotation. A coil support extends from one side of the actuator body. An actuator coil is supported by the coil support and is configured to interact with one or more permanent magnetic elements, typically a pair, to form a voice coil motor. One or more actuator arms extend from an opposite side of the actuator body. Each head gimbal assembly includes a transducer head, typically a magneto-resistive (“MR”) head, which is distally attached to each of the actuator arms. Each magnetic disk includes opposing disk surfaces. Data may be recorded along data annular regions on a single disk surface or both. As such, the head stack assembly may be pivoted such that each transducer head is disposed adjacent to the various data annular regions from adjacent to the outer diameter to the inner diameter of each disk.
As mentioned above, typically a pair of magnetic elements is used to form a voice coil motor. Typically each of the magnetic elements is supported by a magnetic element support plate or mount. The plates may have bent ends that contact each other to form a single loop enclosing the magnetic elements. A magnetic flux path extends in a single loop through the magnetic element support plates and between the two magnetic elements. A leg of the coil is positioned between the two magnetic elements. Current passing through the coil results in a torque being applied to the rotary actuator. A change in direction of the current through the coil results in a change in direction of the torque applied to the rotary actuator.
Accordingly, there is a need in the art for an improved magnetic element support configuration in comparison to the prior art.